The buttons on the 440’s keypad enhance the dial setting functions. The RGE Key is used to manually adjust the range scale. The D Mode Key accesses oscilloscope functions including glitch capture and trend mode. The Hold Key freezes the display. The Backlight Key enables / disables the display backlight. The PROG Key accesses DMM functions like Relative, Record, and Compare modes. The MEM Key accesses user set up mode to change display contrast, baud rate, etc. Also it is used to load and save waveforms. Up to eight waveforms can be saved at once. The T-Base Key adjusts the time per division setting. Finally, the Help Key activates help screens which assist the user with the correct attachment of test leads and provides a tip for using the function selected.